Measured photometric precision as a function of the stellar Gaia magnitude and integration time. The dashed curve represents the photon noise. Results obtained with PyCHEOPS (v1. 0. 0) for light curves extracted using DRP v13 with the default photometric aperture of r = 25 px. The noise is estimated using the minimum error method in all the cases (following Maxted et al. 2022a, this is a conservative estimation). The grey region highlights the expected performance for bright stars (SciReq. 1.1) and faint stars (SciReq. 1.2).